Răspuns:
M,CaSO4= 160g/mol
M,CaCO3- 100g/mol
-calculez masa de carbonat pur
p=m,px100/m,i---> m,p= 500x80/100g= 400g
-calculez masa si moli sulfat de calciu, care se obtine din reactie
1mol....................................1mol
CaCO3 + H2SO4----> CaSO4 + H2O+ CO2
100g.................................160g
400g...............................x
x=m=640gCaSO4
niu=m/M= 640g/160g/mol=4mol CaSO4
Explicație: